In most packaging machines, the products being packaged are conveyed thereto at the same time they are packaged. Some types of products, mainly due to their shape, show certain instability which prevents them from holding their position during conveyance, packaging not being performed correctly. As a result, machines in which different solutions are used for holding the products in position during conveyance and packaging for correct packaging thereof are known.
One solution involves using two facing supports (V-shaped, for example) between which the products are arranged, conveyed and packaged. Conveying means that allow movement of products are arranged below same, and as a result of the supports, the products are held in their transverse position. To prevent them from moving longitudinally, one element preventing the relative longitudinal movement thereof during conveyance is additionally used for each product, thereby being held in position during conveyance and packaging.
In other solutions, due to their shape the products are conveyed on supports to hold them in position, the supports being what hold the products in the position. The products must subsequently be separated from the supports, such that the products reach the desired site by themselves.
This occurs, for example, in packaging machines for packaging products with an unstable shape, such as cabbages or lettuces, where the products are arranged on conveying means for being packaged and subsequently discharged from the machine. For example, the products can be conveyed by means of a conveyor belt during the packaging process in a forward movement direction, and at the end of the belt's path, the packaged products are arranged, for example, in a shrink-wrap tunnel to reduce and adapt the contour of the package to the shape of the product.
Due to the shape of the products, the products can roll or move during packaging and conveyance, so it is necessary to hold them in position during the conveyance for packaging. In the machines disclosed in U.S. Pat. No. 3,618,289A and WO2005037686A2, for example, supports or elements holding the products in position while they are conveyed and packaged are used, it being unnecessary to use any separating system because the supports themselves are part of the conveying means.
In packaging machines for packaging products with an unstable shape, separating systems are known for separating the product (once packaged) from its support, such as the shown in FIG. 1, for example. Each product P′ is arranged on an annular-shaped support 3′ for packaging and conveyance and is conveyed in this manner by conveying means 1′ during packaging. At the end of the conveying means 1′ the products P′ are already packaged and the system comprises conveying means 2′ arranged after the first means to separate a product P′ and its support 3′. The system comprises a stop 4′ at the end of the conveying means 2′, which handles separating the supports 3′ from the products P′. Therefore only the products P′ and not the supports 3′, which can be recirculated to be used again, for example, go to the desired position (at the entrance into a shrink-wrap tunnel, onto a conveyor belt, into a container or into a case, for example). The stop 4′ is fixed and arranged such that the supports 3′ hit it when they reach their position whereas the products P′ exit above it, such that products P′ and supports 3′ are separated in the point. In this case, the supports 3′ hit the stops 4′, and with the aid of an ejector 5′, are moved in a transverse direction T′ with respect to the forward movement direction A′. The ejector 5′ ejects the supports 3′ in the transverse direction T′ and thereby causes them to be ejected from the machine, or it can redirect them to the beginning of the machine to be reused with a new product P′ to be packaged. However, sometimes the product P′ does not exit above the stop 4′ (due to a low conveyance speed, the shape or weight of the product P′, or a poor arrangement of the product P′ itself on the support 3′), causing the product P′ to remain on the conveying means 2′ and generating a jam on the means that requires stopping the packaging machine.
EP2524875A1 discloses a separating system for separating a support and a product arranged on the support, the support comprising a cavity in contact with the product. The system comprises a first output conveyor belt for the products and a second output conveyor belt for the supports on a lower level than the first conveyor belt, a bar at the entrance of the first conveyor belt, and a movable conveyor belt configured for adopting two positions: a first position in which the movable conveyor belt is arranged at the entrance of the second output conveyor belt and the bar is introduced into the cavity of the support and allows the conveyance of the support towards the second output conveyor belt, while at the same time the product remains on the bar; and a second position in which the movable conveyor belt is arranged at the entrance of the first output conveyor belt in contact with the product, the movable conveyor belt conveying the product towards the first output conveyor belt.